DIASTEREOSELECTIVE REDUCTION OF PERFLUQROALKYLATED α,β-UNSATURATED KETONES WITH BAKER’S YEAST
作者:Tomoya Kitazume、Nobuo Ishikawa
DOI:10.1246/cl.1984.587
日期:1984.4.5
The differentiation of a fluorinated group in the molecule with active fermenting yeast and the doubleasymmetricinduction in some perfluoroalkylated α,β-unsaturated ketones are described.
Enzymatic syntheses of chiral building blocks with trifluoromethyl or pentafluoroethyl groups
作者:Tomoya Kitazume、Nobuo Ishikawa
DOI:10.1016/s0022-1139(00)85108-8
日期:1985.9
A number of opticallyactive allylic alcohols with a trifluoromethyl or a pentafluoroethyl group were prepared by the biological reduction of the corresponding ketones with activefermenting baker's yeast.
Synthesis of novel C2-symmetric chiral crownethers and their application to enantioselective trifluoromethylation of aldehydes and ketones are discussed. The use of a series of C2-symmetric chiral crownethers 2 or 3 derived from commercially available (R)-1,1′-bi-2-naphthol for the enantioselective trifluoromethylation of 2-naphthyl aldehyde 1a with (trifluoromethyl)trimethylsilane in the presence
Trifluoromethyl vs. methyl ability to direct enantioselection in microbial reduction of carbonyl substrates.
作者:Alberto Arnone、Rosanna Bernardi、Francesca Blasco、Rosanna Cardillo、Giuseppe Resnati、Igor I. Gerus、Valery P. Kukhar
DOI:10.1016/s0040-4020(98)83017-2
日期:1998.3
The stereoselective reduction of 3-trifluoromethylcyclohexanone (1a), (E)-1.1.1-trifluoro-4-phenyl-3-buten-2-one (3a). and their unfluorinated analogues 1b and 3b has been performed with some growing microorganisms. Differences in the electronic and steric properties of the trifluoromethyl and methyl residues result in different chemo- and stereoselectivities in the microbial reduction of phenylbutenones 3a and 3b while cyclohexanones 1a and 1b showed strictly similar stereoselectivities. A new protocol based on C-13 NMR spectra of 2-phenylpropionic acid esters has been used to assign the absolute configuration of the obtained secondary alcohols. (C) 1998 Elsevier Science Ltd. All rights reserved.
A microbially based approach for the preparation of chiral molecules possessing the trifluoromethyl group